Degree Type

Dissertation

Date of Award

2011

Degree Name

Doctor of Philosophy

Department

Animal Science

First Advisor

Joseph G. Sebranek

Second Advisor

Kenneth J. Prusa

Abstract

Consumers' concerns about nitrite and nitrate consumption led meat processors to begin manufacturing products without adding sodium nitrite or nitrate. The USDA created special labeling requirements for these products requiring the common name followed by "Uncured." The original products within this class were different than traditional cured meats as processors eliminated but did not attempt to replace nitrite. Now, many products within this category utilize a natural nitrate/nitrite source and produce products with traditional cured meat characteristics. In addition, many ingredients commonly added to processed meats to improve product quality and safety are not allowed in products with natural or organic designations. The first study found that these naturally cured products have traditional cured meat characteristics but greater pathogen growth, Clostridium perfringens and Listeria monocytogenes, occurred on many commercial brands of frankfurters, ham, and bacon. Changes in product composition, pH, salt, water activity, and traits related to the curing reaction were correlated to pathogen growth. In the second study, commercially available natural antimicrobials were evaluated for Listeria monocytogenes inhibition in naturally cured ham. Producing naturally cured meats with natural nitrate sources and nitrate reducing starter cultures resulted in greater ingoing nitrite concentrations than when using pre-converted celery powder that already had nitrate reduced to nitrite. Concentration of ingoing nitrite impacted pathogen growth and antimicrobial effectiveness. With greater ingoing nitrite concentrations in the natural nitrate and starter culture system, both clean label antimicrobials effectively inhibitedL. monocytogenes growth over 35 days of storage at 4y C. The antimicrobials had little impact on other product characteristics. For the third study, a simplified model system was developed to simulate and determine the effects of the curing system on nitrite chemistry. Although nitrite is slowly formed by bacterial reduction of naturally cured meats, this model showed the rate of nitrite addition did not affect nitrosation/nitrosylation reactions. As expected, greater amounts of sodium nitrite increased the nitrosation/nitrosylation reactions and confirmed that myoglobin undergoes nitrosylation before cysteine is nitrosated. Increased ingoing nitrite concentrations in combination with natural antimicrobials may allow production of naturally cured meats with quality and safety characteristics comparable to their conventionally cured counterparts.

DOI

https://doi.org/10.31274/etd-180810-2479

Copyright Owner

Gary Anthony Sullivan

Language

en

Date Available

2012-04-30

File Format

application/pdf

File Size

129 pages

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